Strainer for pumps.



W.l S. DUNSTEDTER. STRAINER Pon PUMPS.

APFLIUATION FILED FEB. 28, 1908. Patented Feb. 9, 1909.

UNITED .STATESl PATENT OFFICE.

l. WILLIAM s. DUNs'InDTER,1 or PoAe, ILLINOIS.

s'rRAINnR Fon PUMPS.

p y Specification of Letters Patent.

Application filed February 28, 1908. Serial No. 418,269. l

Patented Feb. 9, 1909.

frequently oceursthat the water line will become lowered` during theoperation of a pump to such an extent that air will be rawn through thestrainer tube of the well tube andinto the pump with the result ofinterfering with the capacity. and proper' action of the pump.

The object of my invention is the provision of means to prevent thesucking of air through the strainer tubes of pumps of the.

kind named when the waterline in the well tube in which a pump is 'beingused becomes lower than the top of the strainer tube.

Figure I is a vertical section of the deep well tube havingmyimprovement incorporated therein. Fig. II is a cross section taken online II-lI, Fig. I.

1 designates .a deep well tube to which a pump of any ordinaryconstruction may be apphed and'2 is a strainer tube which constitutes apart of the well tube and is adapted to extend downwardly into the earthin which water is supplied to the well tube. The strainer tube 2 is aform of device commonly utilized in deep well pumps and no invention perse is herein claimed therefor.

It frequently occurs 'that the water line which should normally be aboveall of the erforations in the strainer tube becomes ibwered to suchperforations and as a conseqluence air is sucked .through theperforations in the strainer tube to theV interior thereof and drawntherefrom -to the pump. To obviate the occurrence just mentionedIprovide an inner tube 3 which is positioned within the strainerl tubeand is concentric therewith, this inner tube being supported from thetop of the strainer tube. and eX- fastenedtogether by bolts?.

tended downwardly in the strainer tube from the position above theperforations therein to a position considerably beneath the uppermostperforations of the strainer tube and preferably to a position near thebottom of the strainer tube.4 The inner tube 3 su ports and is open tocommunication with t e well tube 1 at its upperiend and is provided w1than inlet opening for the water at its lower end. The inlet opening ofsaid tube is controlled by a check valve 4 of any suitable kind Y In.the practical useof a pump having my# well tube construction the watermust necessarily gain the entrance into the well tube by passing to thelower end of the inner tube 8 and at a point very much beneath the upperperforated portion of the strainer tube 2 so t iat there is nopossibilit -of air bein@` sucked into the `well tube an the action ofthe pump is consequently at all times "a normal one. I

To provide against the occurrence of a vacuum in the space between theuppaer unperforated portion of the strainer tu e and the upper portionof the inner tube 3,1 a ply to the upper unperforated portion of t e.strainer tube Ian air conducting inlet pipe 5 that leads into the spacejust mentioned and through which air may be delivered downwardly intosaid space from the surface of the ground. The air conducting inlet pipeis provided with a cut-off valve 6.

By this invention the pumps will get the full capacity of the strainertube and well tube. Without this the umps will suck mostly from the topof tie strainer tube which has a tendency to clog the lower part of thestrainer tube and thus decrease the capacity ofthe well. A

The strainer tube 2A is rovided with a flange 2a at the top upon w lichisseated the supporting flange 3a of the inner tube 3 which in turnreceives the lange 1a of the well tube l the three flanges beingsecurely I claim: l

The 'combination of a perforated sti-amer,

formed with an lmperforate upper part havin i 1 00v a flange,an/imperforate inner tube forme with a supporting flange at its upperend ,'r/ r seated upon the flange of the stramer tube, f and connectedthrough the mxpvrlm-nie vrp-f and provlded Wlth a verticallyreelproeetmg per pal-t 01"' the simmer wfn im #www iwcheek Vave at itslower end, a, Well tube tween the strainer tube :n

formed with ay :Gange seatedf'upon the sup porting ange of the nnex'tube, means for seeming the flanges together and an ai' conducting inletpipe having e controlling vave

